Note that this works almost the same as ruby's haml, but doesn't pretty print the html. This would greatly slow down and complicate the code. If you really want pretty printed html, then I suggest writing one using the xml parser library and process the resulting html..

API

Haml(haml) -> template(locals) -> html

This is the new (as of 0.2.0) way to generate haml templates. A haml template is a live function that takes in "this" context and a "locals" variable. This compile step takes a few milliseconds to complete so it should be done at startup and the resulting function should be cached. Then to use the template function you simply call it with the desired local variables and it will output html at blazing speeds (we're talking millions per second on my 13" MBP)

Compile and store a template:

var main = Haml(main_haml);

Then use it whenever you need a new version:

main({name: "Tim", age: 28});

That's it. Haml templating made easy!

If you want to store the generated javascript to a file to skip the compile step later on you can either decompile the template function or use the compile and optimize advanced functions directly.

Haml.compile(text) -> JavaScript compiled template

Given a haml template as raw text, this compiles it to a javascript expression
that can later be eval'ed to get the final HTML.

Haml.optimize(js) -> optimized JavaScript expression

Takes the output of compile and optimizes it to run faster with the tradeoff of longer compile time. This is useful for framework developers wanting to use haml in their framework and want to cache the compiled templates for performance.

Code interpolation

New in version 0.2.0 there is string interpolation throughout. This means that the body of regular text areas can have embedded code. This is true for attributes and the contents of plugins like javascript and markdown also. If you notice an area that doesn't support interpolation and it should then send me a note and I'll add it.

Plugins

There are plugins in the parser for things like inline script tags, css blocks, and support for if statements and for loops.

:if statements

if statements evaluate a condition for truthiness (as opposed to a strict comparison to true) and includes the content inside the block if it's truthy.

:if todolist.length > 20
%p Oh my, you are a busy fellow!

:each loops

:each loops allow you to loop over a collection including a block of content once for each item. You need to what variable to pull the data from and where to put the index and value. The index variable is optional and defaults to __key__.

Here is an example over a simple array.

%ul.todolist
:each item in todolist
%li= item.description

You can loop over the keys and values of objects too (Note the inner :each loop)

Get Involved

If you want to use this project and something is missing then send me a message. I'm very busy and have several open source projects I manage. I'll contribute to this project as I have time, but if there is more interest for some particular aspect, I'll work on it a lot faster. Also you're welcome to fork this project and send me patches/pull-requests.

About Performance

The haml compiler isn't built for speed, it's built for maintainability. The actual generated templates, however are blazing fast. I benchmarked them with over 65 million renders per second on a small (20 line) template with some dynamic data on my laptop. Compare this to the 629 compiles per second I got out of the compiler. The idea is that you pre-compile your templates and reuse them on every request. While 629 per second is nothing compared to 65 million, that still means that your server with over 600 different views can boot up in about a second. I think that's fine for something that only happens every few weeks.